IOMMU: Add SDF Support

This commit adds iommu support to microkit sdfs.

Define a constant to represent the a tool enforced limitation on
the maximum virtual address suported for an IO address space. This
is due to current x86 IOMMU behaviour in the kernel which
dynamically detects the maximum virtual address for an IO address space.
For more info read: BOOT_CODE bool_t vtd_init_num_iopts(uint32_t num_drhu) in
seL4/src/plat/pc99/machine/intel-vtd.c.

Add PciDevice struct and PCIDeviceParseError enum. This types
allow us to implement the Display trait which gives a consistent way
to output PCI information. The FromStr trait implemented for PCIDevice
avoid duplicating logic required to parse the PCI identifier from the xml.
When combined with the display trait on the PCIDeviceParseError, we get
consistent error messages and avoid repeating code.

Add IOMMUDeviceIdentifier and IOMMUDeviceIdentifierParseError to support
parsing the sdf based on the current architecture. This allows the sdf parsing
to easily support ARM SMMU and RISCV IOMMU. The Display traits again
remove repeated code when outputting IOMMUDeviceIdentifer or
IOMMUDeviceIdentifierParseError, particularly useful for error messages.

Add SysIOMapPerms. Representing the perms in an enum completely removes
the existence of invalid IOMapPerms once we parse the sdf.

Add SysIOMap. The dual to SysMap, used to represent a mapping in a devices
IO virtual address space.

Replace ExecutionContext trait with a Map trait. The previous trait was primarily
used in the check_maps function to handle memory regions in virtual machines and
normal pds. This Map trait allowed the one check_maps function to handle both
SysIOMaps and SysMaps uniformly. The additional information that was provided
by the polymorhpic ExecutionContext is just passed as a string to be used
in the respective error message. This is because outside of the check_maps function
a protection_domain and a virtual_machine are handled as distinct types.

Add error checking cases to check_maps. If the map_start + mr.size overflows
alot of the pre-exisiting logic breaks so check for it. Also check that we don't overflow
the top of user_virtual memory accouting for the differences between protection_domains,
virtual_machines and io address spaces.

Add check_io_maps adapter. Required because check_maps is designed to error check
within one address space. Therefore we collect all the mappings that have been made
on a per IO address space basis.

capdl/irq.rs waas using the old pci_bus,pci_dev,pci_func form. Since we have a
real type now, we updated the expected match form.

Signed-off-by: Callum <c.berry@student.unsw.edu.au>

Author: cazb2

example/x86_64_iommu_dma_test/x86_64_iommu_dma_test.system

@@ -0,0 +1,20 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!--
+ Copyright 2026, UNSW
+
+ SPDX-License-Identifier: BSD-2-Clause
+-->
+<system>
+    <memory_region name="edu_mmio_window" size="0x10_0000" page_size="0x1000" phys_addr="0xfe00_0000" />
+    <memory_region name="dma_buffer" size="0x1000" page_size="0x1000" />
+    <io_address_space name="QEMU EDU" identifier="0:4.0">
+        <iomap mr="dma_buffer" iovaddr="0x10_0000" />
+    </io_address_space>
+
+    <protection_domain name="x86_64_iommu_dma_test" priority="100">
+        <program_image path="x86_64_iommu_dma_test.elf" />
+        <map mr="edu_mmio_window" vaddr="0x2000_0000" perms="rw" cached="false" setvar_vaddr="edu_mmio_window_vaddr" />
+        <map mr="dma_buffer" vaddr="0x3000_0000" perms="rw" cached="true" setvar_vaddr="dma_buffer_vaddr" />
+        <ioport id="0" addr="0xcf8" size="8" setvar_id="pci_config_ioport_id" />
+    </protection_domain>
+</system>

tool/microkit/src/capdl/irq.rs

@@ -86,18 +86,14 @@ fn create_irq_obj(
             }),
         }),
         SysIrqKind::MSI {
-            pci_bus,
-            pci_dev,
-            pci_func,
-            handle,
-            ..
+            pci_device, handle, ..
         } => Object::IrqMsi(object::IrqMsi {
             slots: [].to_vec(),
             extra: Box::new(object::IrqMsiExtraInfo {
                 handle: Word(handle),
-                pci_bus: Word(pci_bus),
-                pci_dev: Word(pci_dev),
-                pci_func: Word(pci_func),
+                pci_bus: Word(pci_device.bus as u64),
+                pci_dev: Word(pci_device.device as u64),
+                pci_func: Word(pci_device.function as u64),
             }),
         }),
     };